Substrate processing apparatus and substrate processing method

ABSTRACT

A substrate such as a semiconductor wafer is transferred to a plurality of process chambers so as to perform prescribed processes. An inspection chamber is air-tightly connected to each of the process chambers. The inspection chamber is provided with a handler which loads and unloads the substrate. A gate valve is disposed between each process chamber and the inspection chamber. By this gate valve, each chamber is air-tightly closed.

This application is a divisional of application Ser. No. 08/036,894,filed Mar. 25, 1993, now U.S. Pat. No. 5,766,360.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate processing apparatus forperforming prescribed processes (such as performing a thin film growthprocess) for a semiconductor substrate used for producing asemiconductor device such as a VLSI. (Very Large Scale Integration)device and a substrate processing method.

2. Description of the Related Art

Thin film growth technologies for growing a thin film on the surface ofa semiconductor substrate are one of the key technologies for enhancingthe performance of semiconductor devices. In particular, thin filmgrowth technologies using the CVD (Chemical Vapor Deposition) methodhave been widely employed.

Conventionally, substrate processing apparatuses of this type, such as athin film growth apparatus, are designed to perform particular processessuch as growing a thin film on the surface of a substrate, such as asemiconductor wafer. The thin film which has been formed on thesubstrate is evaluated by another apparatus in the next process afterthe substrate on which the thin film was formed on the surface thereofhas been unloaded from the thin film forming apparatus (substrateprocessing apparatus).

Thus, it takes a long time for the result of evaluation of the thin filmwhich has been formed on the substrate to be obtained.

However, in this case, while the substrate is being processed andevaluated, the surface of the thin film may be contaminated or thecharacteristics of the film may change.

In a single wafer processing apparatus, from the view point of qualityassurance of a processed substrate, the evaluation of the process shouldbe performed with a high frequency. Thus, when the substrate isevaluated by another apparatus, much labor and time are consumed. Inaddition, when the evaluation of the process result takes a long time,unnecessary processes will be continued for a defective substrate.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above describeddifficulties. An object of the present invention is to provide asubstrate processing apparatus and a substrate processing method bywhich a thin film and the like can be quickly and easily evaluatedalmost immediately after the thin film and the like have been formed andby which the yield of the growth of the thin film can be increased.

The present invention in a first aspect thereof provides a substrateprocessing apparatus, comprising a process chamber for performing aprescribed process for a semiconductor substrate, an inspection chamber,connected to the process chamber, for performing a predeterminedanalysis for the semiconductor substrate, and a transfer means forloading and unloading the semiconductor substrate between the processchamber and the inspection chamber.

The present invention in a second aspect thereof provides a substrateprocessing apparatus, comprising a thin film growth chamber for forminga thin film on the surface of the semiconductor substrate, a gas supplyunit for supplying a supply gas to the thin film growth chamber, a gasexhaust unit for exhausting a gas from the thin film growth chamber, anexhaust gas analyzing unit, connected to the gas exhaust unit, foranalyzing the amount, the composition or both the amount and compositionof an exhaust gas, and a record/analysis/determination means, forsetting the amount and composition of the supply gas supplied to thethin film growth chamber and process conditions of the thin film growthchamber, wherein the record/analysis/determination means is adapted toevaluate a thin film of the semiconductor substrate according to anexhaust gas analytic result received from the exhaust gas analyzingunit.

The present invention in a third aspect thereof provides a substrateprocessing apparatus, comprising a plurality of process chambers forperforming prescribed processes with respect to a semiconductorsubstrate, and a plurality of transfer chambers, connected to theprocess chambers, the transfer chambers having transfer means forloading and unloading the semiconductor substrate to each of the processchambers, wherein a load lock chamber having a load lock mechanism isdisposed between the transfer chambers, the load lock mechanism beingadapted to substitute the atmosphere in the transfer chamber with airatmosphere or vacuum atmosphere.

The present invention in a fourth aspect thereof provides a substrateprocessing method of a semiconductor substrate processing apparatushaving a process chamber for performing a prescribed process withrespect to a semiconductor substrate an inspection chamber, connectableto the process chamber, for performing a predetermined analysis for thesemiconductor substrate, and a transfer means for loading and unloadingthe semiconductor substrate between the process chamber and theinspection chamber, the method comprising the steps of (a) analyzing thesemiconductor substrate in the inspection chamber and storing analyticinformation in an analytic information storage means, (b) transferringthe semiconductor substrate from the inspection chamber to the outsidethereof, and (c) analyzing the analytic information, wherein thetransfer means is adapted to perform the step (b), and wherein ananalytic information analysis means is adapted to perform the step (c).

The present invention in a fifth aspect thereof provides a substrateprocessing method for supplying a supply gas to a thin film growthchamber and for evaluating a thin film formed on the surface of asemiconductor substrate disposed in the thin film growth chamber, themethod comprising the steps of setting the amount and composition of thesupply gas supplied to the thin film growth chamber and processconditions of the thin film growth chamber, and analyzing the amount,the composition or both the amount and composition of an exhaust gasexhausted from the thin film growth chamber and evaluating the thin filmaccording to an analytic result of the exhaust gas.

These and other objects, features and advantages of the presentinvention will become more apparent in light of the following detaileddescription of best mode embodiments thereof, as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram showing the basic construction of asubstrate processing apparatus and a substrate processing method of afirst embodiment according to the present invention;

FIG. 2 is a schematic diagram showing a modification of the firstembodiment;

FIG. 3 is a schematic diagram showing the basic construction of a secondembodiment according to the present invention;

FIG. 4 is a schematic diagram showing a modification of the secondembodiment;

FIG. 5 is a schematic diagram showing the basic construction of a thirdembodiment according to the present invention;

FIG. 6 is a schematic diagram showing the basic construction of a fourthembodiment according to the present invention;

FIG. 7 is a schematic diagram showing a modification of the fourthembodiment; and

FIG. 8 is a schematic diagram showing another modification of the fourthembodiment.

DESCRIPTION OF PREFERRED EMBODIMENTS

First Embodiment

Now, with reference to the accompanying drawings, the first embodimentof the present invention will be described.

FIGS. 1 and 2 are schematic diagrams showing a thin film growthapparatus according to a first embodiment of the present invention, FIG.1 showing the basic construction thereof. In FIG. 1, reference numeral 1designates the thin film growth apparatus. The thin film growthapparatus 1 comprises two process chambers which are a thin film growthchamber 2 and a substrate pre-process chamber 3. The thin film growthchamber 2 grows a thin film on a substrate. The substrate pre-processchamber 3 performs a pre-process such as etching a substrate. Theprocess chambers 2 and 3 are connected to an inspection chamber 6through gate valves 4 and 5, respectively. The inspection chamber 6performs prescribed analyses of a semiconductor substrate 15. Inaddition, the inspection chamber 6 is connected to a defective substratestorage chamber 9 and a load/unload chamber 10 through gate valves 7 and8, respectively. Moreover, the inspection chamber 6 has a transfer meanssuch as a handler 13. The handler 13 transfers a semiconductor substrate15 between each chamber. The thin film growth apparatus 1 furthercomprises a control unit 11 which controls the chambers 2 and 3, theinspection chamber 6, the defective substrate storage chamber 9, theload/unload chamber 10, the handler 13, and the gate valves 4, 5, 7, and8.

Substrates 15 which are held in a cassette or the like are transferredfrom a clean room (not shown in the figure). The substrates 15 are setin the load/unload chamber 10. Next, the atmosphere in the load/unloadchamber 10 is substituted with the atmosphere of a vacuum, an inert gas,or another gas such as H₂. The substrates 15 are transferred sheet bysheet to the inspection chamber 6 by the handler 13 which operates in aninterlocking relationship with the open and close operations of the gatevalve 8. The inspection chamber 6 measures the surface distribution ofthe thickness of the substrate 15. Thereafter, the substrate 15 istransferred from the inspection chamber 6 to the substrate pre-processchamber 3 by the handler 13 which operates in an interlockingrelationship with the open and close operations of the gate valve 5.

The substrate pre-process chamber 3 performs a pre-process such asremoving a natural oxide film formed on the surface of the substrate 15.For example, the substrate pre-process chamber 3 deaerates air or gasfrom the inside thereof and sprays an HF (hydrogen fluoride) gas orvapor gas on the surface of the substrate 15 so as to dry-etch thenatural oxide film on the surface of the substrate 15. Then, thesubstrate 15 is transferred from the substrate pre-process chamber tothe inspection chamber 6 by the handler 13 which operates in aninterlocking relationship with the open and close operations of the gatevalve 5.

Next, the inspection chamber 6 analyzes the surface of the substrate 15received from the pre-process chamber 3 so as to inspect and determinewhether or not the natural oxide film is present on the surface of thesubstrate 15. After the inspection chamber 6 determines that the naturaloxide film is absent from the surface of the substrate 15, the substrate15 is transferred from the inspection chamber 6 to the thin film growthchamber 2 by the handler 13 which operates in an interlockingrelationship with the open and close operations of the gate valve 4.When the natural oxide film is present on the surface of the substrate15, the substrate 15 is transferred from the inspection chamber 2 to thesubstrate pre-process chamber 3 so as to remove the natural oxide filmtherefrom. If the natural oxide film cannot be removed from thesubstrate 15 with the removing process performed a specific number oftimes, the substrate 15 is transferred from the substrate pre-processchamber 3 to the defective substrate storage chamber 9 or theload/unload chamber 10 without the thin film growth process. It shouldbe noted that the surface of the substrate 15 can be analyzed by thesubstrate pre-process chamber 3 rather than the inspection chamber 6.

The thin film growth chamber 2 performs a thin film growth process forthe substrate 15. For example, the thin film growth chamber 2 suppliesSiH₄ and H₂ gases while heating the substrate 15. The substrate 15 isfor example a semiconductor wafer of Si (silicon) single crystalsubstrate. Thereafter, the substrate 15 is transferred from the thinfilm growth chamber 2 to the inspection chamber 6 by the handler 13which operates in an interlocking relationship with the open and closeoperations of the gate valve 4.

The inspection chamber 6 inspects the substrate 15 for necessaryinspection items selected from evaluation items such as the thickness ofgrowth film, resistivity, composition, surface conditions, particles,metal impurities, crystal defects, and film interface conditions.

In this case, the thickness of the growth thin film can be obtained bymeasuring the surface distribution of the total thickness of thesubstrate and the growth thin film and comparing it with the thicknessof the original substrate. In this manner, even for a specimen whichcannot be measured without being destroyed for measurement, the filmthickness thereof can be positively and non-destructively measured.

The resistivity can be measured by using a contact method such as thefour-terminal method. The position of the measurement of the resistivityshould be selected so that the orientation flat of the substrate 15always becomes constant. This position is preferably a position which isnot used for a device on the substrate 15. In addition, the resistivitycan be measured by a non-contact method such as the eddy current method.

When the growth thin film of the substrate 15 deviates from apredetermined standard, the control unit 11 receives a relevant signalfrom the inspection chamber 6 and determines that the growth thin filmis defective.

The inspection result of each substrate 15 is recorded and stored in thecontrol unit 11. The inspection result can be referenced in the laterprocesses.

The thin film growth chamber 2 may be of a batch type instead of asingle wafer processing type. In the case of the single wafer processingtype, a growth thin film on a substrate 15 may be inspected. When a testpiece is used, a growth test piece may be inspected.

The metal impurities can be inspected by for example an emissionspectrochemical analysis. However, this inspection generally takes along time. This time is longer than the time for which a thin filmgrows. Thus, a sampling test is performed. By preparing a plurality ofinspection units in the inspection chamber 6, the throughput of theinspections can be improved.

When defective substrates 15 occur frequently, the control unit 11issues an alarm so as to minimize the defective ratio of the substrates15. However, it is possible to automatically stop the apparatus 1. Whenthe film growth conditions can be fed back, if the inspection resultdeviates largely from the standard value of the thin film, the controlunit 11 can feed back the data to the thin film growth chamber 2.

When a substrate 15 is determined to be defective, the subsequentinspections or processes are be omitted. When a particular substrate 15cannot be removed from the process sequence, the processes can becontinued.

It should be noted that the above-mentioned process sequence is only anexample and is not a limitation thereof. For example, if necessary,inspections before the thin film growth process can be omitted, theseinspections including the pre-process.

In the process sequence, although it is preferable not to expose thesubstrate to exterior gas such as air, the present invention is notlimited thereto.

The entire apparatus can be disposed in a vacuum atmosphere, an inertatmosphere, or another controlled gas atmosphere.

FIG. 2 is a schematic diagram showing a modification of the firstembodiment. In the figure, reference numeral 20 designates a thin filmgrowth apparatus. The thin film growth apparatus comprises twoload/unload chambers 21 and 22, two handler chambers 29 and 39, and fourprocess chambers. These process chambers are connected to each of thehandler chambers 29 and 39. The process chambers are a substratepre-process chamber 34, two thin film growth chambers 50 and 51, anorientation flat alignment chamber 43, and an inspection chamber 58. Thesubstrate pre-process chamber 34 performs preprocesses. The thin filmgrowth chambers 50 and 51 grow thin films on substrates. The orientationflat alignment chamber 43 aligns a substrate 15 with an orientation flatdisposed thereon. The inspection chamber 58 performs various analysessimilar to those performed by the inspection chamber of the embodimentshown in FIG. 1.

Substrates 15 which were pre-processed and held in cassettes or the likeare transferred from for example a clean room (not shown in the figure)and set in the chambers 21 and 22 through doors 23 and 24 thereof.

The substrates 15 set in the first and second load/unload chambers 21and 22 are transferred sheet by sheet to the handler chamber (transferchamber) 29 by a first handler (transfer means) 30 disposed therein, thefirst handler 30 operating in an interlocking relationship with the openand close operations of gate valves 25 and 26. Next, a substrate 15 istransferred from the first handler chamber 29 to the substratepre-process chamber 34 by the first handler 30 which operates in aninterlocking relationship with the open and close operations of a gatevalve 33. After the substrate 15 is loaded in the substrate pre-processchamber 34, the pre-process chamber 34 deaerates gas or air from theinside thereof and performs a pre-process such as etching a naturaloxide substance on the surface of the substrate 15 with a HF (hydrogenfluoride) gas or the like.

Next, the substrate 15 is transferred from the pre-process chamber 34 tothe second handler chamber 38 by a second handler 39 disposed therein,the second handler 39 operating in an interlocking relationship with theopen and close operations of a gate valve 35. Then, the substrate 15 inthe handler chamber 38 is transferred to the orientation flat alignmentchamber 43 by the second handler 39 which operates in an interlockingrelationship with the open and close operations of a gate valve 42.

The orientation flat alignment chamber 43 detects the position of theorientation flat disposed on the substrate 15 and aligns the position ofthe substrate 15 in a predetermined direction. When the orientation flatalignment process is not necessary or another orientation flat alignmentprocess is used, the orientation flat alignment chamber 43 can beomitted. In addition, the orientation flat alignment chamber 43 canobtain the thickness of a growth thin film by measuring the thickness ofthe substrate 15 before and after the thin film is grown.

Thereafter, the substrate 15 is transferred from the orientation flatalignment chamber 43 to the first or second thin film growth chamber 50or 51 by the second handler 39 which operates in an interlockingrelationship with the open and close operations of a gate valve 46 or47, respectively. When a HF gas was used in the pre-process (etchingprocess) the thin film growth chamber 50 or 51 radiates ultraviolet raysto the surface of the substrate 15 so as to remove the F (fluorine)therefrom. Thereafter, the thin film growth chamber 50 or 51 performs aprescribed thin film growth process while supplying predetermined gasesso as to form a thin film on the surface of the substrate 15.

After the thin film growth process is completed, the substrate 15 istransferred from the first or second thin film growth chamber 50 or 51to the second handler chamber 38 by the second handler 39 which operatesin an interlocking relationship with the open and close operations of agate valve 46 or 47, respectively. The substrate 15 in the handlerchamber 38 is transferred to the substrate pre-process chamber 34 by thesecond handler 39 which operates in an interlocking relationship withthe open and close operations of a gate valve 35. Thereafter, thesubstrate 15 is transferred from the first handler chamber 29 to theinspection chamber 58 by the first handler 30 which operates in aninterlocking relationship with the open and close operations of gatevalves 33 and 61.

As in the embodiment shown in FIG. 1, the inspection chamber 58 performsvarious measurements and inspections for the thin film formed on thesubstrate 15.

After these inspections are completed, the substrate 15 is transferredfrom the inspection chamber 58 to the first handler chamber 29 by thefirst handler 30 which operates in an interlocking relationship with theopen and close operations of a gate valve 61. Thereafter, the substrate15 in the handler chamber 29 is held in a cassette disposed in the firstor second load/unload chamber 21 or 22 by the handler 30. Thus, theprocess sequence is completed.

The substrate pre-process chamber 34 is provided with a load lockmechanism which changes the atmosphere in the chamber 34 to airatmosphere or vacuum atmosphere. The volume of the substrate pre-processchamber 34 is less than that of each of the other chambers 21, 22, 29,38, 43, 50, 51, and 58. Thus, the deaerating process or air atmosphererestoring process can be easily performed.

As described above, according to the above-mentioned embodiment, almostjust after a thin film was grown, it can be quickly evaluated. Thus, theyield of the thin film and so forth can be improved and the decrease ofthe throughput of the apparatus can be minimized. In addition, thequality assurance of the thin film and so forth can be easily performed.

Second Embodiment

FIGS. 3 and 4 are schematic diagrams showing a thin film growthapparatus according to a second embodiment of the present invention,FIG. 3 showing the basic construction thereof. In FIG. 3, referencenumeral 101 is a thin film growth apparatus which comprises two processchambers: a thin film growth chamber 102 and a substrate pre-processchamber 103. The thin film growth chamber 102 performs a thin filmgrowth process for growing a thin film on a substrate 115. The substratepre-process chamber 103 performs a pre-process such as etching thesubstrate 115. The process chambers 102 and 103 are connected to ahandler chamber 106 through gate valves 104 and 105. The handler chamber106 has a handler 119. The handler chamber 106 is connected to aload/unload chamber 108 through a gate valve 107. In addition, thehandler chamber 106 is connected to an inspection chamber 110 through agate valve 109.

Analytic information of the substrate 115 obtained by the inspectionchamber 110 is stored in an analytic information storage means 111. Theinformation stored in the analytic information storage means 111 isretrieved and analyzed by an analytic information analysis means 112.The analytic result of the analytic information analysis means 112 issent to a control means 113. The control means 113 controls the processchambers 102 and 103, the handler chamber 106, the load/unload chamber108, the inspection chamber 109, and the analytic information storagemeans 111. As described above, analytic information stored in theanalytic information storage means 111 is analyzed by the analyticinformation analysis means 112 and thereby the analytic result isobtained. The analytic result is sent to the control means 113.

Substrates which are held in a cassette or the like and transferred froma clean room (not shown in the figure) are set in the load/unloadchamber 108. Thereafter, the substrates 115 are transferred sheet bysheet to the handler chamber 106 by the handler 119 which operates in aninterlocking relationship with the open and close operations of the gatevalve 107. Thereafter, a substrate 115 is transferred from theload/unload chamber 108 to the substrate pre-process chamber 103 by thehandler 119 which operates in an interlocking relationship with the openand close operations of the gate valve 105.

The substrate pre-process chamber 103 performs a pre-process such asremoving an organic substance, a natural oxide film, and so forthadhering to the surface of the substrate (semiconductor wafer) 115. Thesubstrate pre-process chamber 103 deaerates air or gas from the insidethereof and sprays a HF (hydrogen fluoride) gas, vapor gas, or the liketo the surface of the substrate 115 so as to dry-etch a natural oxidefilm on the surface of the substrate 115. After the pre-process of thesubstrate 115 is completed, the substrate 115 is transferred from thepre-process chamber 103 to the handler chamber 106 by the handler 119which operates in an interlocking relationship with the open and closeoperations of the gate valve 105. Thereafter, the substrate 115 istransferred from the handler chamber 106 to the inspection chamber 110by the handler 119 which operates in an interlocking relationship withthe open and close operations of the gate valve 109.

Using for example an ellipsometer, the inspection chamber 110 analyzesthe surface of the semiconductor substrate 115 which was pre-processedso as to determine whether or not the result of the pre-process isproper. In other words, with the ellipsometer, the film thickness offive points on the surface of the semiconductor substrate 115 ismeasured. In this case, the polarizing angle and light intensity of fivepoints are measured. The resultant data (analytic information) is storedin the analytic information storage means 111. Thereafter, the substrate115 is transferred from the inspection chamber 110 to the handlerchamber 106 by the handler 119 which operates in an interlockingrelationship with the open and close operations of the gate valve 109.

The measurement for obtaining analytic information of light intensitynormally takes a time on the order of several seconds. However, theanalysis of this information for obtaining the film thickness takes atime on the order of several minutes. Thus, the analytic informationobtained in the inspection chamber 110 is temporarily stored in theanalytic information storage means 111. Thereafter, the substrate 115 istransferred from the inspection chamber 110 to the handler chamber 106.During subsequent processes of the substrate 115 (such as a substratetransfer process and performing an epitaxial growth process), theabove-mentioned analytic information is retrieved from the analyticinformation storage means 111 and analyzed by the analytic informationanalysis means 112. Since the film thickness data is analyzed by theanalytic information analysis means 112 after the substrate 115 istransferred from the inspection chamber 110 to the outside thereof, thetime necessary for analyzing the analytic information can be shortened.

In other words, if the substrate 115 is transferred from the inspectionchamber 110 to the handler chamber 106 after the analytic informationwas analyzed, due to a waiting time for the analysis time on the orderof several minutes, the throughput decreases. However, since theanalysis by the analytic information analysis means 112 is performedwhile other processes of the substrate 115 are being performed, theprocess time can be shortened.

Next, the substrate 115 is transferred from the handler chamber 106 tothe thin film growth chamber 102 by the handler 119 which operates in aninterlocking relationship with the open and close operations of the gatevalve 104. It should be noted that the surface analysis of the substrate115 can be performed by the substrate pre-process chamber 103 ratherthan the inspection chamber 110.

The thin film growth chamber 102 performs an epitaxial growth processfor the substrate 115 by supplying a SiH₄ gas and a H₂ gas while heatingthe substrate 115. The substrate 115 is a Si (silicon) single crystalsubstrate. After the epitaxial growth process is completed, thesubstrate 115 is transferred from the thin film growth chamber 102 tothe handler chamber 106 by the handler 119 which operates in aninterlocking relationship with the gate valve 104. Thereafter, thesubstrate 115 is transferred from the handler chamber 106 to theinspection chamber 110 by the handler 119 which operates in aninterlocking relationship with the open and close operations of the gatevalve 109.

Thereafter, the inspection chamber 110 inspects the substrate 15 fornecessary inspection items selected from evaluation items such as thethickness of growth film, resistivity, composition, surface conditions,particles, metal impurities, crystal defects, and film interfaceconditions. For example, the film thickness of the substrate on which athin film was grown is measured by FTIR (Fourier Transform InfraredSpectrophotometer).

In the analysis using the FTIR, to obtain analytic information of onepoint, it takes several seconds. However, to analyze the analyticinformation and to calculate the required film thickness, it takesseveral ten seconds. Thus, in the same manner as the pre-process, theanalytic information obtained by the inspection chamber 110 istemporarily stored in the analytic information storage means 111. Next,the substrate 115 is transferred from the inspection chamber 110 to thehandler chamber 106. While a subsequent process for the substrate 115 isbeing performed (namely, during a handling process in which the nextsubstrate 115 is being transferred to the inspection chamber 110), theanalytic information is analyzed by the analytic information analysismeans 112. When the analytic information analysis means 112 analyzesmeasured data of epitaxial film thickness, the time necessary formeasuring the film thickness can be shortened.

The analysis items inspected by the inspection chamber 110 are notlimited to those described above. Besides the film thickness of thesubstrate 115, after supply gas and exhaust gas of the thin film growthchamber 102 and the substrate pre-process chamber 103 are analyzed, theanalytic information can be sent to the analytic information storagemeans 111 so as to analyze the analytic information.

It should be noted that the above-mentioned process sequence and theconstruction of the apparatus are only examples, and are notlimitations. For example, if necessary, inspections before the thin filmgrowth process can be omitted, the inspections including thepre-processing step.

FIG. 4 is a schematic diagram showing a modification of the secondembodiment. In the figure, reference numeral 120 is a thin film growthapparatus. The thin film growth apparatus comprises two load/unloadchambers 121 and 122, two handler chambers 129 and 138, and four processchambers. These process chambers are connected to each of the handlerchambers 129 and 138. The process chambers are a substrate pre-processchamber 134, two thin film growth chambers 150 and 151, an orientationflat alignment chamber 143, and an inspection chamber 158. The substratepre-process chamber 134 performs pre-processes. The thin film growthchambers 150 and 151 grow thin films on substrates. The orientation flatalignment chamber 143 aligns a substrate 115 with an orientation flatdisposed thereon. The inspection chamber 158 performs various analysessimilar to those performed by the inspection chamber of the embodimentshown in FIG. 3.

Substrates 115 which were pre-processed and held in cassettes or thelike are transferred from for example a clean room (not shown in thefigure) and set in the chambers 121 and 122 through doors 123 and 124thereof.

The substrates 115 set in the first and second load/unload chambers 121and 122 are transferred sheet by sheet to the handler chamber 129 by afirst handler 130 disposed therein, the first handler 130 operating inan interlocking relationship with the open and close operations of gatevalves 125 and 126. Next, a substrate 115 is transferred from the firsthandler chamber 129 to the substrate pre-process chamber 134 by thefirst handler 130 which operates in an interlocking relationship withthe open and close operations of a gate valve 133. After the substrate115 is loaded in the substrate pre-process chamber 134, the pre-processchamber 134 deaerates gas or air from the inside thereof and performs apre-process such as etching a natural oxide substance on the surface ofthe substrate 115 with a HF (hydrogen fluoride) gas or the like.

Next, the substrate 115 is transferred from the pre-process chamber 134to the second handler chamber 138 by a second handler 139 disposedtherein, the second handler 139 operating in an interlockingrelationship with the open and close operations of a gate valve 135.Then, the substrate 115 in the handler chamber 138 is transferred to theorientation flat alignment chamber 143 by the second handler 139 whichoperates in an interlocking relationship with the open and closeoperations of a gate valve 142.

The orientation flat alignment chamber 143 detects the position of theorientation flat disposed on the substrate 115 and aligns the positionof the substrate 115 in a predetermined direction. When the orientationflat alignment process is not necessary or another orientation flatalignment process is used, the orientation flat alignment chamber 143can be omitted.

In addition, the orientation flat alignment chamber 143 can obtain thethickness of a growth thin film by measuring the thickness of thesubstrate 115 before and after the thin film is grown.

Thereafter, the substrate 115 is transferred from the orientation flatalignment chamber 143 to the first or second thin film growth chamber150 or 151 by the second handler 139 which operates in an interlockingrelationship with the open and close operations of a gate valve 146 or147, respectively. When a HF gas is used in the pre-process (etchingprocess), the thin film growth chamber 150 or 151 radiates ultravioletrays to the surface of the substrate 115 so as to remove the F(fluorine) therefrom. Thereafter, the thin film growth chamber 150 or151 performs a prescribed thin film growth process while supplyingprescribed gases so as to form a thin film on the surface of thesubstrate 115.

After the thin film growth process is completed, the substrate 115 istransferred from the first or second thin film growth chamber 150 or 151to the second handler chamber 138 by the second handler 139 whichoperates in an interlocking relationship with the open and closeoperations of a gate valve 146 or 147, respectively. The substrate 115in the handler chamber 138 is transferred to the substrate pre-processchamber 134 by the second handler 139 which operates in an interlockingrelationship with the open and close operations of a gate valve 135.Thereafter, the substrate 115 is transferred from the first handlerchamber 129 to the inspection chamber 158 by the first handler 130 whichoperates in an interlocking relationship with the open and closeoperations of gate valves 133 and 166.

As in the embodiment shown in FIG. 3, a measurement unit 157 disposed inthe inspection chamber 158 performs various measurements and inspectionsfor the thin film formed on the substrate 115. This analytic informationis temporarily stored in the analysis information storage means 111 (seeFIG. 3). While the substrate 115 is being processed, the analyticinformation is analyzed by the analytic information analysis means 112(see FIG. 3).

After necessary analytic information is obtained in the inspectionchamber 158, the substrate 115 is transferred from the inspectionchamber 158 to the first handler chamber 129 by the first handler 130which operates in an interlocking relationship with the open and closeoperations of the gate valve 166. Thereafter, the substrate 115 in thehandler chamber 129 is held in a cassette disposed in the first orsecond load/unload chamber 121 or 122 by the handler 130. Thus, theprocess sequence is completed.

The substrate pre-process chamber 134 is provided with a load lockmechanism which changes the atmosphere in the chamber 134 to airatmosphere or vacuum atmosphere. The volume of the substrate pre-processchamber 134 is less than that of each of other chambers 121, 122, 129,138, 143, 150, 151, and 158. Thus, the deaerating process or airatmosphere restoring process can be easily performed.

As described above, according to the above-mentioned embodiment, a thinfilm which was grown on a substrate can be evaluated while anotherprocess is being performed. Thus, the evaluation of the thin film can bequickly performed. Therefore, the yield of the thin film and so forthcan be improved and the decrease of the throughput of the apparatus canbe minimized.

Third Embodiment

FIG. 5 is a schematic diagram showing a thin film growth apparatusaccording to a third embodiment of the present invention. In the figure,the thin film growth apparatus has a thin film growth chamber 201 whichis airtightly disposed therein. The thin film growth chamber 201 has asubstrate holder 203 disposed at the upper end of a rotatable rotationshaft 204, the substrate holder 203 holding a substrate 202. Below thesubstrate holder 203, a heater 205 which heats the substrate 202 and thesubstrate holder 203 is disposed.

An upper portion of the thin film growth chamber 201 is connected to agas supply unit 206 through a supply pipe 207. A lower portion of thethin film growth chamber 201 is connected to an exhaust unit 208 throughan exhaust pipe 209.

The substrate 202 is mounted on the upper surface of the substrateholder 203. The substrate 202 is heated by the heater 205 to aprescribed temperature (from several hundred degrees centigrade to onethousand and several hundred degrees centigrade). Next, the gas supplyunit 206 supplies a raw material gas (for example, AsH₃, SiH₄, or SiH₂)and a carrier gas (for example, H₂) to the thin film growth chamber 201so as to grow a thin film on the substrate 202. When a silicon film isgrown on the substrate 202, a raw material gas such as SiH₂ Cl₂, SiH₄,or Si₂ H₆ is used. In this case, the carrier gas can be omitted.

When the substrate 202 is doped, a gas such as PH₃ or B₂ H₆ is used. Thethin film to be grown is not limited to a silicon film, but other filmssuch as a semiconductor film, an insulation film, a metal film, and anelectrolysis film. When a thin film is grown, the rotation shaft 204 isrotated at for example 500 rpm or more so as to rotate the substrateholder 203 and the substrate 202. At this point, the chamber isdeaerated by the exhaust unit 208 so that the pressure therein becomesconstant (for example, from several Torr to several hundred Torr).

A supply gas analysis unit 210 is disposed in the middle of the supplypipe 207. An exhaust gas analysis unit 211 is disposed in the middle ofthe exhaust pipe 209. The thin film growth chamber 201 is provided witha pressure gauge 212, a radiation thermometer 213, and a rotation meter214. The pressure gauge 212 monitors the pressure of the thin filmgrowth chamber 201. The radiation thermometer 213 monitors thetemperature of the substrate (semiconductor wafer) 202. The rotationmeter 214 monitors the rotational speed of the rotation shaft 204. Theseunits and meters 210 to 214 are connected to arecord/analysis/determination means 215.

The supply gas analysis unit 210 samples and analyzes the supply gassupplied from the gas supply unit 206 through the supply pipe 207 byusing for example FTIR (Fourier Transform Infrared Spectrophotometer)method. This gas analysis can be performed by using another analysismeans such as gas chromatography method or QMS (Quadrupole MassSpectrum) method. Besides the sampling method, the gas which flows inthe supply pipe 207 can be analyzed.

The exhaust gas analysis unit 211 samples and analyzes the exhaust gasexhausted to the exhaust unit 208 through the exhaust pipe 209 by usingfor example FTIR (Fourier Transform Infrared Spectrophotometer) method.The gas can be analyzed by another means.

The record/analysis/determination means 215 sets the temperature of thesubstrate 202, the growth pressure in the thin film growth chamber 201,the rotational speed of the rotation shaft 204, the amount and componentof the supply gas and stores these set values. In addition, therecord/analysis/determination means 215 stores the temperature of thesubstrate, the pressure in the thin film growth chamber, the rotationalspeed of the rotation shaft, the amount and component of the supply gas,and the amount and component of the exhaust gas as reference valuesobtained when a standard thin film is grown.

Moreover, the record/analysis/determination means 215 receives variousinformation from the units and meters 210 to 214 and compares them withreference information which has been stored so as to evaluate the thinfilm formed on the surface of the substrate 202.

In other words, in the range of reproducibility of the apparatus, whenthe same growth conditions are given, the same thin film should beformed. The growth conditions have been set before the thin film isgrown. Normally, the thin film is grown as set in the growth conditions.However, when a thin film is actually grown, the conditions in the thinfilm growth chamber 201 slightly differ in each thin film. Thus, thequality of each thin film deviates.

In this case, the amount and composition of the supply gas, thetemperature of the substrate, the growth pressure, and the number ofrotations of the substrate which largely affect the growth of the thinfilm are monitored. In addition, the amount and composition of theexhaust gas exhausted from the thin film growth chamber 201 aremonitored. With the data monitored, it is determined whether or not theconditions in the thin film growth chamber 201 are in a predeterminedrange. These data are totally determined so as to assure the quality ofthe thin film.

In other words, the record/analysis/determination means 215 compares themonitored results of the growth substrate temperature, the growthpressure, and the rotational speed of the substrate received from theunits and meters 212 to 214 with predetermined set values so as todetermine whether or not the growth thin film is in an allowabledeviation range of the predetermined set values.

Next, the record/analysis/determination means 215 compares the resultsof gas analyses received from the supply gas analysis unit 210 and theexhaust gas analysis unit 211 with the reference values. In thisprocess, the record/analysis/determination means 215 determines whetheror not the components and amount of the supply gas supplied to the thinfilm growth chamber 201 are in allowable ranges. Next, therecord/analysis/determination means 215 determines whether or not thecomponents and amount of the exhaust gas are in allowable ranges. Withthe analytic results, the quality of the thin film can be assured.

Depending on the film growth conditions, monitor items and gas analysisitems which are not necessary for quality assurance can be omitted.

For example, once the amount and composition of the supply gas, thetemperature of the substrate, the growth pressure, the number ofrotations of the substrate, and the gas flow rate are set, they do notlargely deviate from the reference values. Thus, by analyzing only theamount and composition of the exhaust gas, the evaluation of the thinfilm can be simplified. When the thin film growth apparatus does nothave a mechanism which rotates a substrate, it is not necessary tomonitor the number of rotations of the substrate.

Moreover, the determination of whether or not a thin film is allowablecan be manually performed by reading the record of the measured results.

As described above, according to this embodiment, a thin film formed ona substrate can be easily evaluated without an evaluation of the thinfilm itself. In addition, the thin film can be non-contractually,quickly and cheaply evaluated.

Fourth Embodiment

FIGS. 6 to 8 are schematic diagrams showing a thin film growth apparatusaccording to a fourth embodiment of the present invention, FIG. 6showing the basic construction thereof. In FIG. 6, reference numeral 301is the thin film growth apparatus. The thin film growth apparatus 301comprises two handler chambers which are first and second handlerchambers 304 and 305. The first handler chamber 304 has a handler 302.The second handler chamber 305 has a handler 303. The first handlerchamber 304 is connected to three process chambers 309, 310, and 311through gate valves 306, 307, and 308. On the other hand, the secondhandler chamber 305 is connected to a process chamber 312 through a gatevalve 313.

The second handler chamber 305 is connected to a cassette station 315through a load lock chamber 314 which has a load lock mechanism. Theload lock chamber 314 and the cassette station 315 are connected througha gate valve 316. The load lock chamber 314 and the second handlerchamber 305 are connected through a gate valve 317.

The first handler chamber 304 and the second handler chamber 305 areconnected through a gate valve 318, a connection chamber (load lockchamber) 320, and a gate valve 319 which are disposed in this order. Theconnection chamber 320 has a load lock mechanism. The atmospheres of thefirst, and second handler chambers 304 and 305 are separated from eachother by the connection chamber 320. The atmosphere in the first handlerchamber 304 is vacuum or air at a reduced pressure which is used in thenormal sequence. On the other hand, the atmosphere in the second handlerchamber 305 is air at the atmospheric pressure. The load lock mechanismchanges the atmosphere in each chamber to air at atmospheric pressure orvacuum.

In FIG. 6, the process chambers 309 to 311 connected to the firsthandler chamber 304 perform predetermined processes or inspections for asubstrate under vacuum or reduced air pressure. The process chamber 312connected to the second handler chamber 304 performs a predeterminedprocess or inspection under atmospheric pressure.

Practically, the process chamber 309 is a thin film forming chamberwhich forms a thin film such as a silicon epitaxial film on the surfaceof a substrate 325 according to reduced pressure vapor phase epitaxialgrowth method. The process chamber 310 is an oxide film removal chamberwhich etches a natural oxide film adhered on the surface of thesubstrate with for example a HF (hydrogen fluoride) gas under reducedpressure so as to remove it. The process chamber 311 is a clean chamberwhich removes a reaction product which was adhered on the surface of thesubstrate 325 in the oxide film removing process. The process chamber312 removes under atmospheric pressure a protection film which has beenformed on the surface of the substrate 325 in the preceding process. Inaddition, the process chamber 312 forms a protection film on the surfaceof the substrate 325 on which a thin film was formed.

Substrates 325 which were pre-processed and held in a cassette or thelike are transferred from a clean room (not shown in the figure). Thesubstrates 325 are set in the cassette station 315. Next, the substrates325 are transferred sheet by sheet to the load lock chamber 314 by thehandler 303 which operates in an interlocking relationship with the openand close operations of the gate valve 316. Then, the gate valve 316 isclosed and the atmosphere in the load lock chamber 314 is substitutedwith that of the second handler chamber 305.

Next, the substrate 325 in the load lock chamber 314 is transferred tothe process chamber 312 through the handler chamber 305 by the handler303 disposed therein, the handler 303 operating in an interlockingrelationship with the open and close operations of the gate valves 317and 313. When the substrate 325 is loaded in the process chamber 312, itremoves the protection film formed on the surface of the substrate 325.

Then, the substrate 325 is transferred from the process chamber 312 tothe connection chamber 320 by the handler 303 which operates in aninterlocking relationship with the open and close operations of the agate valves 313 and 318. Thereafter, the gate valve 318 is closed andthe atmosphere in the connection chamber 320 is substituted with air atreduced pressure or vacuum. Next, the substrate 325 is transferred fromthe connection chamber 320 to the process chamber (oxide film removechamber) 310 by the handler 302 disposed in the first handler chamber304, the handler operating in an interlocking relationship with the openand close operations of the gate valves 319 and 307. The process chamber310 performs a pre-process which etches a natural oxide substanceadhered on the surface of the substrate 325 with for example a HF(hydrogen fluoride) gas.

Next, the substrate 325 is transferred from the process chamber 310 tothe process chamber (cleaning chamber) 311 by the handler 302 disposedin the first handler chamber 304, the handler 302 operating in aninterlocking relationship with the open and close operations of the gatevalves 307 and 306. The process chamber 311 removes a reaction productsuch as F (fluorine) adhered on the surface of the substrate 325.

Thereafter, the substrate 325 is transferred from the process chamber311 to the process chamber (thin film forming chamber) 309 by thehandler 302 which operates in an interlocking relationship with the openand close operations of the gate valves 308 and 306. The process chamber309 supplies a prescribed gas and performs a prescribed thin film growthprocess so as to form a thin film on the surface of the substrate 325.

Next, the substrate 325 is transferred from the process chamber 309 tothe connection chamber 320 by the handler 302 disposed in the firsthandler chamber 304, the handler 302 operating in an interlockingrelationship with the open and close operations of the gate valves 316and 319. The connection chamber 320 closes the gate valve 319 and theatmosphere therein is substituted with atmospheric air. Then, thesubstrate is transferred from the connection chamber 320 to the processchamber 312 by the handler 303 of the first handler chamber 305, thehandler 303 operating in an interlocking relationship with the open andclose operations of the gate valves 318 and 313. The process chamber 313forms a protection film on the surface of the substrate 325. Thereafter,the substrate 325 is transferred from the process chamber 313 to thecassette station 315 through the load lock chamber 314 in the reversesequence. Then, the substrate 325 is held in a cassette disposed in thecassette station 314. Thus, the process sequence is completed.

When the connection chamber 320 removes a natural oxide film from thesurface of the substrate 325, the oxide film removal chamber (processchamber) 310 can be omitted. In addition, when the first handler chamber304 removes a reaction product which was adhered due to the removal of anatural oxide film, the process chamber (clean chamber) 311 can beomitted. Moreover, when the process chamber (clean chamber) 310connected to the first handler chamber 304, the connection chamber 320,or the first handler chamber 304 removes the protection film formed inthe preceding process, the process chamber 312 can form only theprotection film which protects the thin film formed on the substrate325.

FIG. 7 is a schematic diagram showing a modification of the fourthembodiment. In the figure, reference numeral 330 is a thin film growthapparatus 330. The apparatus 330 comprises two load/unload chambers 331and 332, two handler chambers 335 and 336, and five process chambers 337to 341. The first handler chamber 335 has a handler 333. The secondhandler chamber 336 has a handler 334. The process chambers 337 to 341are connected to each of the handler chambers 335 and 336. Two processchambers 340 and 341 are connected to both the handler chambers 335 and336, each of which is a connection chamber having a load lock mechanism.

The two load/unload chambers 331 and 332 can have a load lock mechanism.

Substrates 325 which were pre-processed and held in cassettes or thelike are transferred from for example a clean room (not shown in thefigure) and set in the chambers 331 and 332 through doors 322 and 343thereof. Next, the atmospheres of the load/unload chambers 331 and 332are substituted with that of the second handler chamber 336.

The substrates 325 set in the first and second load/unload chambers 331and 332 are transferred sheet by sheet to the second handler chamber 336by a handler 334 disposed therein, the handler 334 operating in aninterlocking relationship with the open and close operations of gatevalves 344 and 345. Next, a substrate 325 is transferred from the secondhandler chamber 336 to the connection chamber (process chamber) 340 bythe handler 334 which operates in an interlocking relationship with theopen and close operations of a gate valve 346. The connection chamber340 is an oxide film removal chamber which performs a pre-process forthe substrate 325 so as to remove a natural oxide film therefrom. Whenthe substrate 325 is loaded in the connection chamber 340, it performs apre-process which etches a natural oxide substance adhering to thesurface of the substrate 325 with for example a HF (hydrogen itfluoride) gas.

Next, the substrate 325 is transferred from the connection chamber 340to the first handler chamber 335 by a handler 333 disposed therein, thehandler 333 operating in an interlocking relationship with the open andclose operations of a gate valve 347. Then, the substrate 325 in thefirst handler chamber 335 is transferred to the process chamber(orientation flat alignment chamber) 339 by the handler 333 whichoperates in an interlocking relationship with the open and closeoperations of a gate valve 348.

The process chamber (orientation flat alignment chamber) 339 detects theposition of the orientation flat disposed on the substrate 325 andaligns the position of the substrate 325 in a prescribed direction. Whenthe orientation flat alignment process is not necessary or anotherorientation flat alignment process is used, the process chamber 339 canbe omitted. In addition, the process chamber 339 can obtain thethickness of an epitaxial growth thin film by measuring the thickness ofthe substrate 325 before and after the thin film is grown.

Thereafter, the substrate 325 is transferred from the process chamber339 to the first or second process chamber (first or second thin filmgrowth chamber) 337 or 338 by the handler 333 which operates in aninterlocking relationship with the open and close operations of a gatevalve 349 or 350, respectively. When a HF gas was used in the etchingprocess (pre-process), the process chamber (thin film growth chamber)337 or 338 radiates ultraviolet rays to the surface of the substrate 325so as to remove the F (fluorine) therefrom. Thereafter, the processchamber 337 or 338 performs a thin film growth process while supplyingprescribed gases so as to form a thin film on the surface of thesubstrate 325.

After the thin film growth process is completed, the substrate 325 istransferred from the first or second process chamber 337 or 338 to thefirst handler chamber 335 by the handler 333 which operates in aninterlocking relationship with the open and close operations of a gatevalve 349 or 350, respectively. The substrate 325 in the handler chamber335 is transferred to the process chamber 340 by the handler 333 whichoperates in an interlocking relationship with the open and closeoperations of a gate valve 347. Thereafter, the substrate 325 istransferred from the second handler chamber 336 to the inspectionchamber 341 by the handler 334 which operates in an interlockingrelationship with the open and close operations of gate valves 346 and353. The inspection chamber 341 is provided with a measurement unit 352.

The inspection chamber 341 performs various measurements and inspectionsfor the thin film formed on the substrate 325.

After these inspections are completed, the substrate 325 is transferredfrom the inspection chamber 341 to the second handler chamber 336 by thehandler 334 which operates in an interlocking relationship with the openand close operations of a gate valve 353. Thereafter, the substrate 325in the handler chamber 336 is held in a cassette disposed in the firstor second load/unload chamber 331 or 332 by the handler 334. Thus, theprocess sequence is completed.

The substrate pre-process chamber 340 is provided with a load lockmechanism which changes the atmosphere in the chamber 340 to airatmosphere or vacuum atmosphere. The volume of the substrate pre-processchamber 340 is less than that of each of other chambers 331, 332, 335,336, 337, 338, 339, and 341. Thus, the deaerating process or airatmosphere restoring process can be easily performed.

Next, with reference to FIG. 8, another modification of the fourthembodiment will be described. As shown in the figure, in thismodification, instead of a single large inspection chamber 341, firstand second small inspection chambers 341a and 341b are connected to bothfirst and second handler chambers 335 and 336. Other parts of themodification shown in FIG. 8 are nearly the same as those shown in FIG.7. In this modification, as shown in FIG. 8, a gate valve 351 isdisposed between the first handler chamber 335 and the first inspectionchamber 341a. In addition, a gate valve 353 is disposed between thesecond handler chamber 336 and the second inspection chamber 341b.

As described above, according to this embodiment, it is not necessary tochange the atmospheres in all of a plurality of handler chambers tovacuum. In addition, since the atmosphere in each process chamberconnected to handler chambers is suitably changed, the scope of theapplication of the multi-chamber type substrate processing apparatus canbe widened.

Although the present invention has been shown and described with respectto a best mode embodiment thereof, it should be understood by thoseskilled in the art that the foregoing and various other changes,omissions, and additions in the form and detail thereof may be madetherein without departing from the spirit and scope of the presentinvention.

What is claimed is:
 1. A substrate processing method of a substrateprocessing apparatus having:a process chamber for performing aprescribed process with respect to for a substrate; an inspectionchamber, connectable to said process chamber, for performing aprescribed analysis with respect to said substrate; and transfer meansfor loading and unloading said substrate between said process chamberand said inspection chamber, said method, comprising the steps of:(a)analyzing said substrate in said inspection chamber and storing analyticinformation in analytic information storage means; (b) transferring saidsubstrate from said inspection chamber to the outside thereof; and (c)analyzing said analytic information.
 2. The substrate processing methodas set forth in claim 1,wherein said analyzing step is perfomred whileor after said substrate is processed in said process chamber.
 3. Asubstrate processing method for supplying a supply gas to a thin filmgrowth chamber and for evaluating a thin film formed on the surface of asubstrate disposed in said thin film growth chamber, said methodcomprising the steps of:setting the amount and composition of saidsupply gas supplied to said thin film growth chamber and processconditions of said thin film growth chamber; and analyzing the amountand composition of an exhaust gas exhausted from said thin film growthchamber and evaluating said thin film according to a result of analysisof said exhaust gas.
 4. The substrate processing method as set forth inclaim 3, further comprising the steps of:analyzing the amount andcomposition of said supply gas and measuring the pressure andtemperature of said thin film growth chamber; and evaluating said thinfilm according to a result of analysis of said supply gas, results ofanalysis of said exhaust gas, and the pressure and temperature of saidthin film growth chamber.
 5. The substrate processing method as setforth in claim 4, further comprising the steps of:measuring therotational speed of a substrate holder for holding said semiconductorsubstrate disposed in said thin film growth chamber; and evaluating saidthin film according to a result of analysis of said supply gas, resultsof analysis of said exhaust gas, the pressure and temperature of saidthin film growth chamber, and the rotational speed of said substrateholder.